1. Field of the Invention
This application is directed to a process for the direct regeneration of acidic resin wherein the regeneration vehicle is saturated with anhydrous acid as the eluant. It is more particularly directed to nonaqueous systems wherein the resin is acidic.
2. Description of Prior Art
Acidic resins have been shown to be effective for removing basic nitrogen compounds from lube oils and jet fuels, thereby improving their quality. It is also known that the thermal and light stabilities of lube oils and distillate fuels can be improved by contacting them with acidic (cationic) resins. The exact mechanism for such improvement is not completely known, but it is speculated that it is due to the removal of polar compounds, particularly basic polar compounds from the base oil.
Nitrogen compounds are poisonous to catalysts used for catalytic cracking and hydrocracking. In addition, they produce NO.sub.x emission when the fuel is burned. In nitrogen removal by such processes, cationic exchange resins can be used advantageously owing to their high treating capacity. In order to make the process viable, the spent resin has to be regenerated economically. However, current techniques for resin regeneration utilize aqueous solutions and the attendant problems resulting from the need to switch between aqueous and organic cycles make the process cumbersome and expensive.
Conventionally, acidic aqueous solutions are used in the regeneration of acid resins. The product can be contaminated by water unless the costly step of solvent flushing of the regenerated resin is used before using the resin for a second cycle. In this type of flushing substantially more waste stream is generated. In addition, the aqueous solution is corrosive, which destroys equipment and leads to product contamination by metallic ions such as Fe, Ni, Mo, etc. However, it has now been found that spent acid resin can be regenerated in nonaqueous media avoiding much of the above-described problem areas.